Population Ecology and Community Interactions

Flashcards to review vocabulary related to population ecology and community interactions.

Population

A group of the same species living in the same area.

Community

A group of different species living in the same area.

Ecosystem

A community of living organisms interacting with each other and their physical environment in a specific area.

Biome

Made up of many ecosystems that share similar environmental characteristics and organisms adapted to those conditions.

Allele Frequency

The number of copies of a particular allele divided by the number of copies of all alleles in a population

Natality

The number of new individuals added by birth per 1000 individuals.

Mortality

The number of individuals leaving by death per 1000 individuals.

Exponential Curve (J-curve)

Occurs when there is no limit to population size; constant growth without environmental constraints.

Logistic Curve (S-curve)

Predicts that the population starts off rapidly, slows down as the population reaches a maximum capacity, and shows the effect of a limiting factor.

Carrying Capacity (K)

The maximum number of organisms of a particular species that can be supported in a given environment.

r-strategist

Follows the J-curve, has a short lifespan, and rapid growth followed by rapid death.

K-strategist

Follows the S-curve, has a long lifespan, and reaches a population size that can be sustained (reach carrying capacity).

Biotic Potential

The unrestricted growth of populations resulting in the maximum growth of that population.

Overshoot

Often in J-curve, population exceeds the carrying capacity before it collapses.

Dieback

A sudden sharp reduction in the size of a population that can be caused by disease, environmental stress, or when its numbers exceed the carrying capacity of its habitat.

Limiting Factors

Environmental factors that limit population size.

Density-Dependent Limiting Factors

Predators and competition for food. Control K-strategists

Density-Independent Limiting Factors

Weather patterns and natural disasters. Control r-strategists

Survivorship Curve

A graphical representation that illustrates how different species or populations survive, reproduce, and age.

Type I Curve (Convex Curve)

Low mortality rate; mortality increases with age.

Type II Curve (Diagonal/Linear Curve)

Constant mortality rate; mortality is fairly consistent at all ages.

Type III Curve (Concave Curve)

High mortality rates in early life.

Community

All the populations of different species that interact in a particular location.

Habitat

The place where an organism lives.

Niche

Specific role that an organism plays in the ecosystem or its habitat, involving the organism's interaction with biotic and abiotic factors.

Competition

An interaction between organisms in which both organisms might be harmed (-/-).

Intraspecific Competition

Occurs between organisms of the same species.

Interspecific Competition

Occurs between organisms of different species.

Predation

An interaction where one organism kills the other for food (+/-).

Herbivory

The consumption of plant material by animals.

Symbiosis

A long-term interaction between members of different species.

Parasitism

One organism living in or on another living organism in order to obtain nutrients (+/-).

Commensalism

A relationship in which one organism benefits and the other is not affected (+/0).

Mutualism

A relationship in which both species benefit (+/+).